1. Field of the Invention
The present invention relates to a lens, and more particularly to a lens for attaching to an LED (light emitting diode) package base of a side emitting LED package device or a light emitting device, and for facilitating the light illumination of the side emitting LED device.
2. Description of the Prior Art
Typical light emitting diode (LED) packages comprise a hemispherical lens attached onto an LED chip which may generate and emit light through the hemispherical lens. However, the conventional LED packages are inefficient as they require a large number of LED packages to illuminate the light guide and result in coupling inefficiencies due to relatively small acceptance angles and/or areas.
U.S. Pat. No. 6,679,621 to West et al. discloses one of the typical LED packages comprising a lens coupled to an LED package base, and including a sawtooth portion for reflecting the lights generated and emitted by the LED chips, and for increasing the illuminated areas.
However, the lights reflected by or through the sawtooth portion of the lens may be interfered with each other, or may be offset with each other, such that the illuminated angles and/or areas may not be greatly increased. In addition, some of the light portions may be parallel to some of the inclined surfaces of the sawtooth portion of the lens and may not be suitably reflected by or through the sawtooth portion of the lens.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional lenses for the side emitting LED devices.